Pavlov's Dog is Chasing Schrodinger's Cat
by unoriginal-elizabeth
Summary: Derek/Casey. "Seeing more of each other is the ideal way to make us want to see less of each other."


NOTES: Written for the cliche-bingo challenge.. The cliche was 'Thank God it's Friday...Again: Time Loops.'

DISCLAIMER: Insert standard disclaimer here.

* * *

The ceremony was moving.

The bride was radiant in an ivory, drop-waisted satin dress.

The groom wore a traditional, classic tuxedo.

All in all, everything went smoothly.

* * *

When Casey woke up, it was still dark. It wasn't a gradual waking up – no half-awareness languidly giving way to full consciousness. Courtesy of the arm slung across her waist, she was deprived of a softer, gentler return to reality. Instead, she went from sleep to a state of complete alertness so fast it was like she had been electroshocked.

She did what anyone would do in her situation. She carefully slid her legs over the edge of the bed, until they were touching the floor, then she eased herself out from under the arm so inconsiderately draped over her torso. She felt around the floor grabbing what she sincerely hoped were her clothes – before tiptoeing into the bathroom and noiselessly shutting the door.

There, she dressed as quickly and quietly as possible. She washed her face, and combed her fingers through her hair and pretended that made enough of a difference. Then, not at all ready to face the world – but more willing to face that than the situation in the bedroom, she carefully turned the handle of the bathroom door, and prepared herself for a stealthy getaway.

Only to stop.

She wasn't the sort of person to just run out on a situation – no matter how difficult or unpleasant. She wasn't the sort of person who had one-night stands – but even if she was, she was certain that she wasn't the sort of person who sneaked out on them afterwards. And clearly the general state of affairs, coupled with what had happened a few hours ago (and was never, ever going to happen again), demanded a full and frank discussion. She took a deep breath to steady herself, opened the bathroom door, and stepped forward, ready to face the unpleasant consequences.

She made it as far as the foot of the bed, before turning tail and scurrying back into the bathroom. As she rummaged through her purse, she did a surprisingly good job of convincing herself that this wasn't a retreat, merely a tactical re-evaluation. Then, armed with determination, resolve, and lipstick, she knelt up on the counter and wrote across the (luckily quite large) mirror in Venice Shimmer –

_Derek,_

_I'm sure we both agree that last night was a horrible, terrible mistake, and should never have happened in the first place. Weddings are emotional events, and I was obviously vulnerable after my break up with Luke. I should make it clear that I don't blame you for what happened – your nature is predisposed to exploit weakness. It would be like expecting a lion to walk right past a wounded antelope. However, I'm sure we both realise that this was a freak one-time occurrence, and will never happen again. As such, I would be grateful if you refrained from ever mentioning the subject – either to myself or others. If I find that you do not abide by this simple rule, I will be forced to retaliate by spreading a negative review of your performance (sexual)._

_Casey._

There was just enough mirror, and just enough Venice Shimmer left to write a few last, important directions.

_P.S. Please clean this before you leave the room. _

_P.P.S That is not a request, Derek!_

_

* * *

  
_

The bride carried a bouquet of calla lilies and orchids.

The groom wore a coordinating double ivory calla lily buttonhole.

The theme was continued with pretty little lily place-card holders.

It was elegant, refined, _perfect…_

_

* * *

  
_

"You were drunk, right?" Casey asked, as she slid out of the bed and began picking up her clothes.

"I think I'm still drunk," Derek assured her, as he watched. "And now I'm _blind_," he finished. He flung a hand over his eyes, then peered between his fingers.

She glared at him and stood, protectively clasping her dress to her body. However, this was not the time to be distracted by petty insults. "Fine," she said. "You were drunk and I'm vulnerable – there. We have our excuses."

"I thought you were vulnerable last time," Derek objected.

"So?"

"You can't use the same excuse twice."

She blinked in confusion.

"That's like saying your dog ate your homework every time the teacher asks. You have to mix it up a little, make an effort." He shook his head in mock-sorrow, "I'm disappointed in you, Casey. Where's your keener spirit?"

Casey closed her eyes. "Clearly I'm not in my right mind. _Clearly_."

"I don't know if that counts as an excuse, so much as a…fact of life."

"Well, that's the excuse I'm giving," she said through gritted teeth, "And, since it's never going to happen again, I don't think we need any other ones."

* * *

The venue was beautiful.

The bride recited her own vows, and the groom…

Well, the groom was Ralph.

* * *

Casey squinted up at the hotel ceiling. "Obviously," she offered, in a high, uncomfortable voice, "I was feeling upset about Ralph." She turned to Derek expectantly.

He looked at her for a moment before taking the pillow from behind his head and holding it over his face.

"I don't mean – not in a 'Ralph is _married,'_ kind of way," she hurriedly explained. "More like, '_Ralph _is married?' _Ralph? _I mean – how is _Ralph _ready to make a big emotional commitment before I am? Does that not seem wrong to you?"

The pillow remained over his face as he said, in a muffled voice, "More or less than…?" and waved a hand between them.

"_This_ doesn't count," Casey said. "_This_ is an aberration."

Unfortunately, however, the recurring nature of said aberration meant it couldn't be entirely written off this time. Once was a mistake, twice was a forgivable lapse, but three times – three times was a full-blown pattern.

Accordingly, steps had to be taken.

* * *

The cake was three-tiered and lemon-flavoured, covered with layers of white, fondant icing.

In addition, there were little individual lemon cupcakes, each with a tiny blue butterfly in the centre of the icing.

There was, however, a bad taste in Casey's mouth, and that bad taste was because –

"I thought we had a deal!" she whispered, as she pulled Derek aside.

He extracted his arm from her grip and glared at her. "What?"

"We agreed that we would both bring dates to the next wedding we attended?" she reminded him. "How could you forget?"

"Easy – _you_ said it. Chances were I wasn't even listening in the first place."

"I can't believe you. One thing. I ask you to do _one thing, _one thing that might finally put an end to this…this second circle of hell we're trapped in – and you don't even do it!"

Derek tipped his head back and regarded the chandelier, before blowing out an impatient breath and saying, "Look, it's no big deal. You brought a date, so…we're safe. We're still in the clear."

"For your sake, I hope so," Casey said darkly. "Now go – flirt with the bridesmaids!"

Derek saluted, and as he wandered over to a small flock of bridesmaids, Casey allowed herself to relax. She had a date – Derek had four girls dressed identically, an adequate distraction for even his short attention span.

The cycle was broken.

* * *

"How did this even happen?" she wondered mournfully several hours later. She blew her hair out of her eyes and pushed Derek away half-heartedly.

"Hey – it's not my fault you can't hang on to a date," he said.

She stared at him. "Self-loathing," she said. "It's the only explanation."

* * *

It was easy to see how much the groom loved the bride.

Presumably, she loved him too, but that was lost in the discovery of how much she _also_ loved country music.

* * *

"So," Casey said, as her fingers delicately adjusted the sheet covering her body.

"The band sucked," Derek said.

"'The band _sucked_?'" she repeated. "Derek, you can't use that as an exc…okay, yeah, the band _really_ sucked."

There was a silence.

Derek looked at the watch still on his wrist. "Huh. This happened a lot earlier than usual."

"We don't _have_ a usual," Casey stressed. "Because we both agreed that all those previous times never happened – and _this_ won't ever happen again. Making it an isolated incident. As a matter of fact, once we walk out that door – I'm pretty sure _this_ won't have happened either."

"Yeah," he said, one word that managed to superficially agree with her stance, while also seeming to dismiss everything she had just said. "So – what do we do now?"

"We should probably go back down," she said, without enthusiasm. The last song had been 'Old Flames Can't Hold a Candle to You.'

"Or…" he said, carefully, suddenly a lot closer to her, without seeming to have moved at all. "Since this isn't happening _anyway_, we could just…"

Derek had a point. More importantly, one of the band members had a harmonica.

* * *

The best man made a witty, crowd-pleasing speech that ended with riotous applause.

The mother of the bride told touching, adorable stories about the bride's childhood.

Okay, they made a slight misstep when they allowed the uncle of the groom to take the microphone, but Casey even kind of enjoyed that, secure in the knowledge that –

* * *

"No! No, no, no! No! No – this…this did not just happen!"

"No need to be so loud – I know the drill. Can we schedule the freak-out for tomorrow morning? Eleven thirty, or later," Derek said, turning onto his side.

"No! No! It – how…_you weren't even invited to this wedding! _You don't know anyone here! This – this isn't _possible_." She stared at the shadowy outline of his body in disbelief. The other times, horrific as they were (…afterwards…) at least stood a chance of being explained in terms of mundane proximity and probability, but this – this was inexplicable.

_This was beyond logic or rational thought._

She had a momentary, terrifying vision of herself and Derek, doomed to repeat these same actions over and over again for all eternity, a karmic punishment for unknown transgressions. It made her heart beat faster – it made her feel dizzy and weak.

Derek turned back towards her. "Okay – chill. This," he flicked a finger between them, "is just one of those things."

"One of _those_ things?" She gaped at him. "One of those_ things?"_

"Yes," Derek said firmly. "One of," he made another vague hand gesture, "those things."

"Well that clears everything up," Casey said, folding her arms over her chest. Then she uncrossed her arms in order to pull up and refasten her bra, before crossing them again. Undaunted, she continued, "Please, enlighten me further – tell me, what do plagues, pestilence and famine amount to in your worldview? Minor setbacks?"

He fixed her with an unimpressed look, before explaining (as his gaze slowly slid south), "It's a wedding deal. Think about it – people do stupid stuff at weddings. They wear stupid clothes, they say stupid things, they eat stupid food, and they _dance _to stupid songs. None of it is stuff they'd do normally, but by the time the next one rolls around...they get some kind of wedding amnesia and they do the same things all over again."

Casey thought about this for a moment. "You know," she said slowly, ushering out foreordained nebulous destiny, and welcoming the return of free-will-with-periodic-idiocy into her life with open arms, "That's…actually a pretty good excuse."

"I know," Derek told her chest.

* * *

The bride was…well, technically, there wasn't one.

Or a groom.

Or a ceremony.

Which was why, despite the general excellence of Derek's excuse, Casey felt the need to clarify, "You're sure that 'anniversaries' count, under the stupid things clause?"

Derek's reply was affirmative, if slightly muffled by the fact that he was speaking into her neck. "We're celebrating that a marriage took place, right? That's almost the same thing."

He sounded distracted, and not entirely focused on the subject at hand, but…what he said _was_ true. In a way. And they _were_ in a hotel, which increased the resemblance to a wedding-type-event. Of course, they were _in_ said hotel to celebrate a wedding anniversary that also happened to be the anniversary of their families merging, which decreased the similarities somewhat…or at the very least made everything slightly weirder.

Still, despite the fact that she still had some misgivings, she let the fact that his hands were creeping underneath her top and stroking her bare skin, convince her.

* * *

There were a variety of venues.

The brides were…diverse, the grooms even more so.

The deleted scenes were pretty good too.

* * *

Derek was stupid, and his stupid excuse was stupid, and _she_ was stupid for ever stupidly believing that the stupid excuse that came from his stupid brain, might not be as stupid as stupid Derek stupid always stupid was. Stupid.

The incontrovertible proof of this came on a _family night at home _during the holidays_._ The worst thing was that it wasn't until afterwards that she realised –

"There was no wedding," she hissed, slapping his shoulder.

"What are you talking about? There were four of them!" Derek protested.

"Movies _don't count!_"

"That one does," Derek assured her. "It felt just like the real thing. _Over_ and _over_ and _over_."

She struggled to sit up in the limited amount of space available, as the horrible truth hit her. "We just _defiled _my old bedroom!" she whisper-screamed.

Derek glanced around. "Yeah," he said, sounding _proud _of the fact. He stretched out on the single bed of her girlhood, further tainting her past with his…present.

"Get out," she said as calmly as possible, and pinched him.

* * *

The problem ran deeper than movies with 'Wedding,' 'Marriage,' or 'Hitched!' in the title. The problem extended to cake (obviously), flowers, bubbles and rice, as well as the collected oeuvre of Dolly Parton.

Somehow, they had maneuvered themselves into a Pavlovian response to all things nuptial.

She tried explaining this to Derek. He followed at least part of it (though he seemed to be under the impression that she was _calling_ him a dog), but after he _completely_ misinterpreted her mention of 'psychic secretions,' she just stopped trying.

So obviously, after the preliminary squealing and the tearful hugging, her answer had to be –

"No."

Emily looked at her, hands still grasping Casey's arms from the giddy jumping-up-and-down of mere moments before, and said, "You…won't be my maid of honour?"

"Oh no, no – of course I'll be your maid of honour," Casey assured her. "I meant 'no, you can't get married.' At least, not right _now_," she corrected.

"I'm not getting married right now," Emily pointed out. "Right now, I'm apparently talking my best friend through an episode."

"You've set a date," Casey said, focusing on the most important detail. "I know it's not for a long time, but…from now on, _everything_ is going to be about that date. It's going to be about booking hotels and looking for dresses and choosing bouquets – and as your best friend and maid of honour, I would be expected to play a part in all those discussions, right?"

"You're saying you…don't _want_ to be a part of all that?" Emily asked, slowly.

"Em – of course I do! I want to be part of everything! I want to schedule dress fittings and talk about colour schemes, and help you pick out the invitations…but – I can't. I mean, maybe in a couple of years, but…not right now."

"Okay," Emily said, rubbing Casey's arms understandingly, "Let me talk to my parents and fiancé and see if we can postpone the wedding indefinitely, while you deal with…whatever you have to deal with."

"Really?"

Emily stared at her. "No, Case, not really."

There was nothing else for it, so Casey told her the truth.

After the inevitable detours into 'give me all the details,' and 'how did that even happen?' and 'how did that even happen…again?' Emily snapped back to business. "Let me get this straight. I can't get married" –

"I knew you'd understand – thanks, Em!"

Emily looked at her. "I wasn't finished. So – I can't get married, because you keep sleeping with Derek?"

"It's an involuntary reflex," Casey told her, earnestly.

"Okay," Emily said, nodding. "Stop me if I'm wrong – but couldn't you solve this problem by…_not _sleeping with Derek?"

"Classical conditioning is a lot more complicated than that!"

"Well then, I guess we have two options," Emily said. "Either I can find myself a new maid of honour…"

Casey bit her lip. "Or?"

"Or…you have almost two years to figure out a way to stop sleeping with Derek."

She considered this, and asked, with interest, "You mean like some kind of…aversion therapy?"

"I mean more like…just not sleeping with him."

* * *

In the end, she came up with a plan, and Derek mocked it. Things were looking more normal already.

"So…your solution is for us to spend _more _time together?"

"More non-wedding related time together, yes," Casey emphasised. "Seeing more of each other is the ideal way to make us want to see less of each other."

Derek stared at her, unimpressed. "You seem to be forgetting that I'm not really a fan of spending _any _time with you."

"Exactly!" she said triumphantly. "And to make sure that it stays that way, I think we should remind each other of just how little we do want to see each other."

"By…seeing even more of each other," he pointed out, like it was an inconsistency instead of a stroke of genius.

She took a deep breath and explained patiently, "Tuesday, my place. I'm offering you a night to remember…exactly why we can't stand each other."

* * *

No bride. No groom. No marriage related movies. So, logically, it followed that there was no –

"No," Casey moaned, pulling the sheets over her head.

"What? We totally followed your rule," Derek argued. "I mean, I don't think it's _possible _to see _more _of you." He surreptitiously lifted the sheets. "And it does make me want to see less."

Casey poked her head out. "We were supposed to be getting back to normal – pushing the wedding-weirdness _out _of the picture, not inviting it in!"

She made batting motions with her hands, as if the wedding-weirdness were a physical entity.

"Why don't we just think of it as…compensation for me for having to spend time with you?" Derek suggested, as he watched her. "I know that's how _I'm_ going to think of it."

Casey took a deep breath, and tried to think.

Okay, so Derek apparently had no problem being Pavlov's dog, just as long as he eventually got fed. She, on the other hand, was an intelligent _human being _who refused to jump (…Derek) just because someone rang a bell.

And yes, she could admit the sound of the bell did make her knees buckle, but that was irrelevant, because – barring this one-time slip, she was going to harness the power of critical thought and science for _good._

Starting now.

She cleared her throat. "No – we are _not_ going to think of it like that. Because _this_ never happened." She couldn't help but feel her dramatic pronouncement was slightly marred by the fact that Derek mouthed it along with her, but she resolutely ignored this, and continued. "Now, get dressed and come back tomorrow, so we can figure out what we did wrong."

She had, she thought with sudden, determined optimism, nearly two years to break this cycle. More than enough time.

After all, it wasn't like they could keep going in circles _forever_.


End file.
